The Search for Dark Matter Soldiers On

It's funny how science works sometimes.  We know quite a bit about dark matter, we know it's out there, we know how much of it there is, we know what its effects are, but we don't know what it is. At the very least, we've narrowed things down a bit.  Theories used to range from subatomic particles to black holes to brown dwarfs, now, scientists are pretty sure it's some sort of subatomic particle.

Of course, that's about all we know right now.  Candidates for dark matter currently include WIMP's, or Weakly Interacting Massive Particles, sterile neutrinos, and axions.  WIMP's are about 100 times more massive than electrons, only interact through gravity and the weak nuclear force, and do not interact very well with normal matter.  They do interact with each other, destroying each other and emitting gamma rays while doing so.  At least, this is the theory, because scientists haven't actually discovered one yet.  Next we have sterile neutrinos, a type of neutrino that interacts with fewer things than regular neutrinos, which don't interact with much.  According to the theory, sterile neutrinos only interact with gravity.  Again, they're something we're pretty sure exist, but we don't really have any means of detecting them.  All we can do is measure the effects they have.  Finally, there are axions, which should exist according to nuclear physics in high numbers, but once again, we have yet to detect any.  There is a project devoted to finding them, which should have definitive results in a few years if axions exists.

In any event, dark matter is probably made up of a combination of these various particles, not just one of them.  I suppose this is all good news in the search for dark matter, but it would be nice if we were sure even one of the proposed particles actually existed.  All three are theoretical at this point, and that just makes it difficult for me to get particularly excited.  I'm guessing it'll be another ten years at least before scientists are confident enough on the composition of dark matter to say definitively what it is.

My Other Blogs
Loose on the Internet
Cool Golf News

My Twitter